Bornean Gibbons are also called gray gibbons. They are thin, light, and often covered with gray and black fur. They like to swing themselves between tree limbs with their long arms. Gibbons of the same group often sing to each other as a way of communication. The singing is characterized by whoops followed by a rapid series of bubbly notes.

Bornean Gibbons do not have tails, and this is what makes them different from monkeys. They are the smallest kind of gibbons, but their arms are extremely long. As they walk with their legs, they have to put their arms in the air and move very slowly in order to keep the balance. This is why they often stay on trees because it is easier for them to move faster.